Asthma is a serious chronic health condition particularly in inner-city adolescents, who suffer disproportionately high asthma-related morbidity and mortality that place heavy economic burdens on families and society. Nonetheless, insufficient research efforts have been directed to improve asthma outcomes in this vulnerable population. There is a consensus that adverse asthma outcomes can be ameliorated by an individual's active engagement in adequate self-management. This multi-site randomized controlled study proposes to implement and evaluate a peer-led asthma self-management for adolescents (PLASMA) program that has demonstrated its feasibility and preliminary efficacy in a previous study. PLASMA will be implemented in three cities (Buffalo NY, Baltimore MD, and Memphis TN) that have particularly high rates of pediatric asthma and asthma-related morbidity, and are thus most likely to benefit from the program. PLASMA comprises three main components: (a) peer-leader training; (b) a one-day asthma camp where peer leaders will deliver manualized self-management content recommended by the national guidelines; and (c) bi-monthly peer-leader contacts. Specific aims are: (1) to evaluate the effectiveness of PLASMA in inner-city adolescents with asthma in improving quality of life (primary outcome), and asthma knowledge, attitudes, outcome expectations, self-efficacy, self-management skills, and asthma control, FEV1 (exploratory outcomes) over time, compared to a control group for whom adult leaders will deliver the same program content; (2) to examine the mediating effects of the exploratory outcomes on quality of life; (3) to examine the moderating effects of personal factors (e.g., age, sex, family support) on the intervention's primary and exploratory outcomes; (4) to evaluate the effects of PLASMA on study outcomes in peer leaders (16-20 years); and (5) to determine the economic impact of the intervention. These aims will be accomplished using a two-group randomized controlled trial with 378 adolescents (12-17 years) from the three cities (126 for each site). A total of 42 qualified peer leaders (14 in each site) wll be enrolled based on adult nomination. Eligibility criteria for both peer leaders and adolescent learners include: a current asthma diagnosis; persistent asthma; absence of other chronic or mental illness; inner-city residence; and capability of verbal and written communication in English. Participants will provide data at enrollment (T1), 3 months later (T2), immediately following the camp (T3), and at 3-, 6-, 9-, 12-, and 15-months post-camp (T4- T8). Data will be analyzed using a multi-site hierarchical three-level linear mixed-effects model where level 1 represents repeated measures, level 2 = subject, and level 3 = site. To determine the economic impact of the program, we will measure the direct healthcare costs and total costs of the program, and perform net cost analyses for each type of costs. In addition, we will estimate cost-effectiveness ratios of the PLASMA group compared with the control.